package com.springboot.netty.rpc;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

import java.lang.reflect.Proxy;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class NettyClient {

    private static ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
    private static NettyClientHandler client;
    private int count = 0;

    ////编写方法使用代理模式，获取一个代理对象
    public Object getBean(final Class<?> serviceClass, final String providerName) {

        return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), 
                new Class<?>[]{serviceClass}, (proxy, method, args) -> {
            System.out.println("(proxy, method, args) 进入...." + (++count) + " 次"); //{} 部分的代码，客户端每调用一次 hello, 就会进入到该代码
            if (client == null) {
                initClient();
            }
            //设置要发给服务器端的信息
            //providerName 协议头 args[0] 就是客户端调用 api hello(???)
            // 参数
            client.setParam(providerName + args[0]);
            return executor.submit(client).get();
        });
        
    }

    private void initClient() {
        client = new NettyClientHandler();
        //创建 EventLoopGroup
        NioEventLoopGroup group = new NioEventLoopGroup();
        Bootstrap bootstrap = new Bootstrap();
        bootstrap.group(group)
                .channel(NioSocketChannel.class)
                // 啥意思？
                .option(ChannelOption.TCP_NODELAY, true)
                .handler(new ChannelInitializer<NioSocketChannel>() {
                    @Override
                    protected void initChannel(NioSocketChannel ch) throws Exception {

                        ChannelPipeline pipeline = ch.pipeline();
                        pipeline.addLast(new StringDecoder());
                        pipeline.addLast(new StringEncoder());
                        pipeline.addLast(client);

                    }
                });

        try {
            bootstrap.connect("127.0.0.1", 7000).sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}
